[PATCH v2 2/2] usb: typec: add support for PTN36502 redriver

From: Luca Weiss
Date: Fri Oct 20 2023 - 06:36:16 EST

Add a driver for the NXP PTN36502 Type-C USB 3.1 Gen 1 and DisplayPort
v1.2 combo redriver.

Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
---
drivers/usb/typec/mux/Kconfig | 10 +
drivers/usb/typec/mux/Makefile | 1 +
drivers/usb/typec/mux/ptn36502.c | 444 +++++++++++++++++++++++++++++++++++++++
3 files changed, 455 insertions(+)

diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index 65da61150ba7..816b9bd08355 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -46,4 +46,14 @@ config TYPEC_MUX_NB7VPQ904M
Say Y or M if your system has a On Semiconductor NB7VPQ904M Type-C
redriver chip found on some devices with a Type-C port.

+config TYPEC_MUX_PTN36502
+ tristate "NXP PTN36502 Type-C redriver driver"
+ depends on I2C
+ depends on DRM || DRM=n
+ select DRM_PANEL_BRIDGE if DRM
+ select REGMAP_I2C
+ help
+ Say Y or M if your system has a NXP PTN36502 Type-C redriver chip
+ found on some devices with a Type-C port.
+
endmenu
diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
index 76196096ef41..9d6a5557b0bd 100644
--- a/drivers/usb/typec/mux/Makefile
+++ b/drivers/usb/typec/mux/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_TYPEC_MUX_GPIO_SBU) += gpio-sbu-mux.o
obj-$(CONFIG_TYPEC_MUX_PI3USB30532) += pi3usb30532.o
obj-$(CONFIG_TYPEC_MUX_INTEL_PMC) += intel_pmc_mux.o
obj-$(CONFIG_TYPEC_MUX_NB7VPQ904M) += nb7vpq904m.o
+obj-$(CONFIG_TYPEC_MUX_PTN36502) += ptn36502.o
diff --git a/drivers/usb/typec/mux/ptn36502.c b/drivers/usb/typec/mux/ptn36502.c
new file mode 100644
index 000000000000..72ae38a1b2be
--- /dev/null
+++ b/drivers/usb/typec/mux/ptn36502.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NXP PTN36502 Type-C driver
+ *
+ * Copyright (C) 2023 Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
+ *
+ * Based on NB7VPQ904M driver:
+ * Copyright (C) 2023 Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
+ */
+
+#include <drm/drm_bridge.h>
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_retimer.h>
+
+#define PTN36502_CHIP_ID_REG 0x00
+#define PTN36502_CHIP_ID 0x02
+
+#define PTN36502_CHIP_REVISION_REG 0x01
+#define PTN36502_CHIP_REVISION_BASE_MASK GENMASK(7, 4)
+#define PTN36502_CHIP_REVISION_METAL_MASK GENMASK(3, 0)
+
+#define PTN36502_DP_LINK_CTRL_REG 0x06
+#define PTN36502_DP_LINK_CTRL_LANES_MASK GENMASK(3, 2)
+#define PTN36502_DP_LINK_CTRL_LANES_2 (2)
+#define PTN36502_DP_LINK_CTRL_LANES_4 (3)
+#define PTN36502_DP_LINK_CTRL_LINK_RATE_MASK GENMASK(1, 0)
+#define PTN36502_DP_LINK_CTRL_LINK_RATE_5_4GBPS (2)
+
+/* Registers for lane 0 (0x07) to lane 3 (0x0a) have the same layout */
+#define PTN36502_DP_LANE_CTRL_REG(n) (0x07 + (n))
+#define PTN36502_DP_LANE_CTRL_RX_GAIN_MASK GENMASK(6, 4)
+#define PTN36502_DP_LANE_CTRL_RX_GAIN_3DB (2)
+#define PTN36502_DP_LANE_CTRL_TX_SWING_MASK GENMASK(3, 2)
+#define PTN36502_DP_LANE_CTRL_TX_SWING_800MVPPD (2)
+#define PTN36502_DP_LANE_CTRL_PRE_EMPHASIS_MASK GENMASK(1, 0)
+#define PTN36502_DP_LANE_CTRL_PRE_EMPHASIS_3_5DB (1)
+
+#define PTN36502_MODE_CTRL1_REG 0x0b
+#define PTN36502_MODE_CTRL1_PLUG_ORIENT_MASK GENMASK(5, 5)
+#define PTN36502_MODE_CTRL1_PLUG_ORIENT_REVERSE (1)
+#define PTN36502_MODE_CTRL1_AUX_CROSSBAR_MASK GENMASK(3, 3)
+#define PTN36502_MODE_CTRL1_AUX_CROSSBAR_SW_ON (1)
+#define PTN36502_MODE_CTRL1_MODE_MASK GENMASK(2, 0)
+#define PTN36502_MODE_CTRL1_MODE_OFF (0)
+#define PTN36502_MODE_CTRL1_MODE_USB_ONLY (1)
+#define PTN36502_MODE_CTRL1_MODE_USB_DP (2)
+#define PTN36502_MODE_CTRL1_MODE_DP (3)
+
+#define PTN36502_DEVICE_CTRL_REG 0x0d
+#define PTN36502_DEVICE_CTRL_AUX_MONITORING_MASK GENMASK(7, 7)
+#define PTN36502_DEVICE_CTRL_AUX_MONITORING_EN (1)
+
+struct ptn36502 {
+ struct i2c_client *client;
+ struct regulator *vdd18_supply;
+ struct regmap *regmap;
+ struct typec_switch_dev *sw;
+ struct typec_retimer *retimer;
+
+ struct typec_switch *typec_switch;
+
+ struct drm_bridge bridge;
+
+ struct mutex lock; /* protect non-concurrent retimer & switch */
+
+ enum typec_orientation orientation;
+ unsigned long mode;
+ unsigned int svid;
+};
+
+static int ptn36502_set(struct ptn36502 *ptn)
+{
+ bool reverse = (ptn->orientation == TYPEC_ORIENTATION_REVERSE);
+ unsigned int ctrl1_val = 0;
+ unsigned int lane_ctrl_val = 0;
+ unsigned int link_ctrl_val = 0;
+
+ switch (ptn->mode) {
+ case TYPEC_STATE_SAFE:
+ /* Deep power saving state */
+ regmap_write(ptn->regmap, PTN36502_MODE_CTRL1_REG,
+ FIELD_PREP(PTN36502_MODE_CTRL1_MODE_MASK,
+ PTN36502_MODE_CTRL1_MODE_OFF));
+ return 0;
+
+ case TYPEC_STATE_USB:
+ /*
+ * Normal Orientation (CC1)
+ * A -> USB RX
+ * B -> USB TX
+ * C -> X
+ * D -> X
+ * Flipped Orientation (CC2)
+ * A -> X
+ * B -> X
+ * C -> USB TX
+ * D -> USB RX
+ */
+
+ /* USB 3.1 Gen 1 only */
+ ctrl1_val = FIELD_PREP(PTN36502_MODE_CTRL1_MODE_MASK,
+ PTN36502_MODE_CTRL1_MODE_USB_ONLY);
+ if (reverse)
+ ctrl1_val |= FIELD_PREP(PTN36502_MODE_CTRL1_PLUG_ORIENT_MASK,
+ PTN36502_MODE_CTRL1_PLUG_ORIENT_REVERSE);
+
+ regmap_write(ptn->regmap, PTN36502_MODE_CTRL1_REG, ctrl1_val);
+ return 0;
+
+ default:
+ if (ptn->svid != USB_TYPEC_DP_SID)
+ return -EINVAL;
+
+ break;
+ }
+
+ /* DP Altmode Setup */
+
+ switch (ptn->mode) {
+ case TYPEC_DP_STATE_C:
+ case TYPEC_DP_STATE_E:
+ /*
+ * Normal Orientation (CC1)
+ * A -> DP3
+ * B -> DP2
+ * C -> DP1
+ * D -> DP0
+ * Flipped Orientation (CC2)
+ * A -> DP0
+ * B -> DP1
+ * C -> DP2
+ * D -> DP3
+ */
+
+ /* 4-lane DP */
+ ctrl1_val |= FIELD_PREP(PTN36502_MODE_CTRL1_MODE_MASK,
+ PTN36502_MODE_CTRL1_MODE_DP);
+ link_ctrl_val |= FIELD_PREP(PTN36502_DP_LINK_CTRL_LANES_MASK,
+ PTN36502_DP_LINK_CTRL_LANES_4);
+ break;
+
+ case TYPEC_DP_STATE_D:
+ case TYPEC_DP_STATE_F: /* State F is deprecated */
+ /*
+ * Normal Orientation (CC1)
+ * A -> USB RX
+ * B -> USB TX
+ * C -> DP1
+ * D -> DP0
+ * Flipped Orientation (CC2)
+ * A -> DP0
+ * B -> DP1
+ * C -> USB TX
+ * D -> USB RX
+ */
+
+ /* USB 3.1 Gen 1 and 2-lane DP */
+ ctrl1_val |= FIELD_PREP(PTN36502_MODE_CTRL1_MODE_MASK,
+ PTN36502_MODE_CTRL1_MODE_USB_DP);
+ link_ctrl_val |= FIELD_PREP(PTN36502_DP_LINK_CTRL_LANES_MASK,
+ PTN36502_DP_LINK_CTRL_LANES_2);
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ /* Enable AUX monitoring */
+ regmap_write(ptn->regmap, PTN36502_DEVICE_CTRL_REG,
+ FIELD_PREP(PTN36502_DEVICE_CTRL_AUX_MONITORING_MASK,
+ PTN36502_DEVICE_CTRL_AUX_MONITORING_EN));
+
+ /* Enable AUX switch path */
+ ctrl1_val |= FIELD_PREP(PTN36502_MODE_CTRL1_AUX_CROSSBAR_MASK,
+ PTN36502_MODE_CTRL1_AUX_CROSSBAR_SW_ON);
+ if (reverse)
+ ctrl1_val |= FIELD_PREP(PTN36502_MODE_CTRL1_PLUG_ORIENT_MASK,
+ PTN36502_MODE_CTRL1_PLUG_ORIENT_REVERSE);
+ regmap_write(ptn->regmap, PTN36502_MODE_CTRL1_REG, ctrl1_val);
+
+ /* DP Link rate: 5.4 Gbps (HBR2) */
+ link_ctrl_val |= FIELD_PREP(PTN36502_DP_LINK_CTRL_LINK_RATE_MASK,
+ PTN36502_DP_LINK_CTRL_LINK_RATE_5_4GBPS);
+ regmap_write(ptn->regmap, PTN36502_DP_LINK_CTRL_REG, link_ctrl_val);
+
+ /*
+ * For all lanes:
+ * - Rx equivalization gain: 3 dB
+ * - TX output swing control: 800 mVppd
+ * - Pre-emphasis control: 3.5 dB
+ */
+ lane_ctrl_val = FIELD_PREP(PTN36502_DP_LANE_CTRL_RX_GAIN_MASK,
+ PTN36502_DP_LANE_CTRL_RX_GAIN_3DB) |
+ FIELD_PREP(PTN36502_DP_LANE_CTRL_TX_SWING_MASK,
+ PTN36502_DP_LANE_CTRL_TX_SWING_800MVPPD) |
+ FIELD_PREP(PTN36502_DP_LANE_CTRL_PRE_EMPHASIS_MASK,
+ PTN36502_DP_LANE_CTRL_PRE_EMPHASIS_3_5DB);
+ regmap_write(ptn->regmap, PTN36502_DP_LANE_CTRL_REG(0), lane_ctrl_val);
+ regmap_write(ptn->regmap, PTN36502_DP_LANE_CTRL_REG(1), lane_ctrl_val);
+ regmap_write(ptn->regmap, PTN36502_DP_LANE_CTRL_REG(2), lane_ctrl_val);
+ regmap_write(ptn->regmap, PTN36502_DP_LANE_CTRL_REG(3), lane_ctrl_val);
+
+ return 0;
+}
+
+static int ptn36502_sw_set(struct typec_switch_dev *sw, enum typec_orientation orientation)
+{
+ struct ptn36502 *ptn = typec_switch_get_drvdata(sw);
+ int ret;
+
+ ret = typec_switch_set(ptn->typec_switch, orientation);
+ if (ret)
+ return ret;
+
+ mutex_lock(&ptn->lock);
+
+ if (ptn->orientation != orientation) {
+ ptn->orientation = orientation;
+
+ ret = ptn36502_set(ptn);
+ }
+
+ mutex_unlock(&ptn->lock);
+
+ return ret;
+}
+
+static int ptn36502_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
+{
+ struct ptn36502 *ptn = typec_retimer_get_drvdata(retimer);
+ int ret = 0;
+
+ mutex_lock(&ptn->lock);
+
+ if (ptn->mode != state->mode) {
+ ptn->mode = state->mode;
+
+ if (state->alt)
+ ptn->svid = state->alt->svid;
+ else
+ ptn->svid = 0; // No SVID
+
+ ret = ptn36502_set(ptn);
+ }
+
+ mutex_unlock(&ptn->lock);
+
+ return ret;
+}
+
+static int ptn36502_detect(struct ptn36502 *ptn)
+{
+ struct device *dev = &ptn->client->dev;
+ unsigned int reg_val;
+ int ret;
+
+ ret = regmap_read(ptn->regmap, PTN36502_CHIP_ID_REG,
+ &reg_val);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to read chip ID\n");
+
+ if (reg_val != PTN36502_CHIP_ID)
+ return dev_err_probe(dev, -ENODEV, "Unexpected chip ID: %x\n", reg_val);
+
+ ret = regmap_read(ptn->regmap, PTN36502_CHIP_REVISION_REG,
+ &reg_val);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to read chip revision\n");
+
+ dev_dbg(dev, "Chip revision: base layer version %lx, metal layer version %lx\n",
+ FIELD_GET(PTN36502_CHIP_REVISION_BASE_MASK, reg_val),
+ FIELD_GET(PTN36502_CHIP_REVISION_METAL_MASK, reg_val));
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_PANEL_BRIDGE)
+static int ptn36502_bridge_attach(struct drm_bridge *bridge,
+ enum drm_bridge_attach_flags flags)
+{
+ struct ptn36502 *ptn = container_of(bridge, struct ptn36502, bridge);
+ struct drm_bridge *next_bridge;
+
+ if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
+ return -EINVAL;
+
+ next_bridge = devm_drm_of_get_bridge(&ptn->client->dev, ptn->client->dev.of_node, 0, 0);
+ if (IS_ERR(next_bridge)) {
+ dev_err(&ptn->client->dev, "failed to acquire drm_bridge: %pe\n", next_bridge);
+ return PTR_ERR(next_bridge);
+ }
+
+ return drm_bridge_attach(bridge->encoder, next_bridge, bridge,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+static const struct drm_bridge_funcs ptn36502_bridge_funcs = {
+ .attach = ptn36502_bridge_attach,
+};
+
+static int ptn36502_register_bridge(struct ptn36502 *ptn)
+{
+ ptn->bridge.funcs = &ptn36502_bridge_funcs;
+ ptn->bridge.of_node = ptn->client->dev.of_node;
+
+ return devm_drm_bridge_add(&ptn->client->dev, &ptn->bridge);
+}
+#else
+static int ptn36502_register_bridge(struct ptn36502 *ptn)
+{
+ return 0;
+}
+#endif
+
+static const struct regmap_config ptn36502_regmap = {
+ .max_register = 0x0d,
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int ptn36502_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct typec_switch_desc sw_desc = { };
+ struct typec_retimer_desc retimer_desc = { };
+ struct ptn36502 *ptn;
+ int ret;
+
+ ptn = devm_kzalloc(dev, sizeof(*ptn), GFP_KERNEL);
+ if (!ptn)
+ return -ENOMEM;
+
+ ptn->client = client;
+
+ ptn->regmap = devm_regmap_init_i2c(client, &ptn36502_regmap);
+ if (IS_ERR(ptn->regmap)) {
+ dev_err(&client->dev, "Failed to allocate register map\n");
+ return PTR_ERR(ptn->regmap);
+ }
+
+ ptn->mode = TYPEC_STATE_SAFE;
+ ptn->orientation = TYPEC_ORIENTATION_NONE;
+
+ mutex_init(&ptn->lock);
+
+ ptn->vdd18_supply = devm_regulator_get_optional(dev, "vdd18");
+ if (IS_ERR(ptn->vdd18_supply))
+ return PTR_ERR(ptn->vdd18_supply);
+
+ ptn->typec_switch = fwnode_typec_switch_get(dev->fwnode);
+ if (IS_ERR(ptn->typec_switch))
+ return dev_err_probe(dev, PTR_ERR(ptn->typec_switch),
+ "Failed to acquire orientation-switch\n");
+
+ ret = regulator_enable(ptn->vdd18_supply);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable vdd18\n");
+
+ ret = ptn36502_detect(ptn);
+ if (ret)
+ goto err_disable_regulator;
+
+ ret = ptn36502_register_bridge(ptn);
+ if (ret)
+ goto err_disable_regulator;
+
+ sw_desc.drvdata = ptn;
+ sw_desc.fwnode = dev->fwnode;
+ sw_desc.set = ptn36502_sw_set;
+
+ ptn->sw = typec_switch_register(dev, &sw_desc);
+ if (IS_ERR(ptn->sw)) {
+ ret = dev_err_probe(dev, PTR_ERR(ptn->sw),
+ "Failed to register typec switch\n");
+ goto err_disable_regulator;
+ }
+
+ retimer_desc.drvdata = ptn;
+ retimer_desc.fwnode = dev->fwnode;
+ retimer_desc.set = ptn36502_retimer_set;
+
+ ptn->retimer = typec_retimer_register(dev, &retimer_desc);
+ if (IS_ERR(ptn->retimer)) {
+ ret = dev_err_probe(dev, PTR_ERR(ptn->retimer),
+ "Failed to register typec retimer\n");
+ goto err_switch_unregister;
+ }
+
+ return 0;
+
+err_switch_unregister:
+ typec_switch_unregister(ptn->sw);
+
+err_disable_regulator:
+ regulator_disable(ptn->vdd18_supply);
+
+ return ret;
+}
+
+static void ptn36502_remove(struct i2c_client *client)
+{
+ struct ptn36502 *ptn = i2c_get_clientdata(client);
+
+ typec_retimer_unregister(ptn->retimer);
+ typec_switch_unregister(ptn->sw);
+
+ regulator_disable(ptn->vdd18_supply);
+}
+
+static const struct i2c_device_id ptn36502_table[] = {
+ { "ptn36502" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ptn36502_table);
+
+static const struct of_device_id ptn36502_of_table[] = {
+ { .compatible = "nxp,ptn36502" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ptn36502_of_table);
+
+static struct i2c_driver ptn36502_driver = {
+ .driver = {
+ .name = "ptn36502",
+ .of_match_table = ptn36502_of_table,
+ },
+ .probe = ptn36502_probe,
+ .remove = ptn36502_remove,
+ .id_table = ptn36502_table,
+};
+module_i2c_driver(ptn36502_driver);
+
+MODULE_AUTHOR("Luca Weiss <luca.weiss@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("NXP PTN36502 Type-C driver");
+MODULE_LICENSE("GPL");

--
2.42.0